diff --git a/miniupnpc/addr_is_reserved.c b/miniupnpc/addr_is_reserved.c
index 046380e..411b12e 100644
--- a/miniupnpc/addr_is_reserved.c
+++ b/miniupnpc/addr_is_reserved.c
@@ -62,7 +62,7 @@ int addr_is_reserved(const char * addr_str)
 		return 1;
 #else
 	/* was : addr_n = inet_addr(addr_str); */
-	if (inet_pton(AF_INET, addr_str, &addr_n) < 0) {
+	if (inet_pton(AF_INET, addr_str, &addr_n) <= 0) {
 		/* error */
 		return 1;
 	}
diff --git a/miniupnpc/minissdpc.c b/miniupnpc/minissdpc.c
index 7f68fc5..8d51d6f 100644
--- a/miniupnpc/minissdpc.c
+++ b/miniupnpc/minissdpc.c
@@ -716,7 +716,7 @@ ssdpDiscoverDevices(const char * const deviceTypes[],
 #endif
 #else
 			/* was : mc_if.s_addr = inet_addr(multicastif); */ /* ex: 192.168.x.x */
-			if (inet_pton(AF_INET, multicastif, &mc_if.s_addr) < 0) {
+			if (inet_pton(AF_INET, multicastif, &mc_if.s_addr) <= 0) {
 				mc_if.s_addr = INADDR_NONE;
 			}
 #endif